Ear sensor

ABSTRACT

An ear sensor provides a sensor body having a base, legs extending from the base and an optical housing disposed at ends of the legs opposite the base. An optical assembly is disposed in the housing. The sensor body is flexed so as to position the housing over a concha site. The sensor body is unflexed so as to attach the housing to the concha site and position the optical assembly to illuminate the concha site. The optical assembly is configured to transmit optical radiation into concha site tissue and receive the optical radiation after attenuation by pulsatile blood flow within the tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority benefit under 35 U.S.C. § 119(e)to U.S. Provisional Patent Application Ser. No. 61/152,964, filed Feb.16, 2009, titled Ear Sensor, hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

Pulse oximetry systems for measuring constituents of circulating bloodhave gained rapid acceptance in a wide variety of medical applications,including surgical wards, intensive care and neonatal units, generalwards, home care, physical training, and virtually all types ofmonitoring scenarios. A pulse oximetry system generally includes anoptical sensor applied to a patient, a monitor for processing sensorsignals and displaying results and a patient cable electricallyinterconnecting the sensor and the monitor. A pulse oximetry sensor haslight emitting diodes (LEDs), typically one emitting a red wavelengthand one emitting an infrared (IR) wavelength, and a photodiode detector.The emitters and detector are typically attached to a finger, and thepatient cable transmits drive signals to these emitters from themonitor. The emitters respond to the drive signals to transmit lightinto the fleshy fingertip tissue. The detector generates a signalresponsive to the emitted light after attenuation by pulsatile bloodflow within the fingertip. The patient cable transmits the detectorsignal to the monitor, which processes the signal to provide a numericalreadout of physiological parameters such as oxygen saturation (SpO₂) andpulse rate.

Pulse oximeters capable of reading through motion induced noise aredisclosed in at least U.S. Pat. Nos. 6,770,028, 6,658,276, 6,650,917,6,157,850, 6,002,952, 5,769,785, and 5,758,644; low noise pulse oximetrysensors are disclosed in at least U.S. Pat. Nos. 6,088,607 and5,782,757; all of which are assigned to Masimo Corporation, Irvine,Calif. (“Masimo”) and are incorporated by reference herein. An earsensor is disclosed in U.S. Pat. No. 7,341,559 titled Pulse Oximetry EarSensor, also assigned to Masimo and also incorporated by referenceherein.

Advanced physiological monitoring systems may incorporate pulse oximetryin addition to advanced features for the calculation and display ofother blood parameters, such as carboxyhemoglobin (HbCO), methemoglobin(HbMet) and total hemoglobin (Hbt), as a few examples. Advancedphysiological monitors and corresponding multiple wavelength opticalsensors capable of measuring parameters in addition to SpO₂, such asHbCO, HbMet and Hbt are described in at least U.S. patent applicationSer. No. 12/056,179, filed Mar. 26, 2008, titled Multiple WavelengthOptical Sensor and U.S. patent application Ser. No. 11/366,208, filedMar. 1, 2006, titled Noninvasive Multi-Parameter Patient Monitor, bothincorporated by reference herein. Further, noninvasive blood parametermonitors and corresponding multiple wavelength optical sensors, such asRainbow™ adhesive and reusable sensors and RAD-57™ and Radical-7™monitors for measuring SpO₂, pulse rate, perfusion index (PI), signalquality (SiQ), pulse variability index (PVI), HbCO and HbMet among otherparameters are also available from Masimo.

SUMMARY OF THE INVENTION

FIG. 1 illustrates various areas of the ear 100 that are amenable toblood parameter measurements, such as oxygen saturation (SpO₂). An earsite has the advantage of more quickly and more accurately reflectingoxygenation changes in the body's core as compared to peripheral sitemeasurements, such as a fingertip. Conventional ear sensors utilize asensor clip on the ear lobe 110. However, significant variations in lobesize, shape and thickness and the general floppiness of the ear loberender this site less suitable for central oxygen saturationmeasurements than the concha 120 and the ear canal 130. Disclosed hereinare various embodiments for obtaining noninvasive blood parametermeasurements from concha 120 and ear canal 130 tissue sites.

One aspect of an ear sensor optically measures physiological parametersrelated to blood constituents by transmitting multiple wavelengths oflight into a concha site and receiving the light after attenuation bypulsatile blood flow within the concha site. The ear sensor comprises asensor body, a sensor connector and a sensor cable interconnecting thesensor body and the sensor connector. The sensor body comprises a base,legs and an optical assembly. The legs extend from the base to detectorand emitter housings. An optical assembly has an emitter and a detector.The emitter is disposed in the emitter housing and the detector isdisposed in the detector housing. The legs have an unflexed positionwith the emitter housing proximate the detector housing and a flexedposition with the emitter housing distal the detector housing. The legsare moved to the flexed position so as to position the detector housingand emitter housing over opposite sides of a concha site. The legs arereleased to the unflexed position so that the concha site is graspedbetween the detector housing and emitter housing.

In various embodiments, the ear sensor has a resilient frame and a onepiece molded .skin disposed over the resilient frame. A cup is disposedproximate the detector housing and has a surface that generally conformsto the curvature of the concha site so as to couple the detector to theconcha site and so as to block ambient light. A sensor cable has wiresextending from one end of the sensor cable and disposed within channelsdefined by the resilient frame. The wires electrically and mechanicallyattach to the optical assembly. A connector is attached to the other endof the sensor cable, and the cable wires electrically and mechanicallyattach to the connector so as to provide communications between theconnector and the optical assembly.

In other embodiments, a stabilizer maintains the position of thedetector housing and the emitter housing on the concha site. Thestabilizer may have a ring that encircles the legs. The ring has a holdposition disposed against the legs and a release position spaced fromthe legs. A release, when pressed, moves the ring from the hold positionto the release position, allowing the ring to slidably move along thelegs in a direction away from the base so as to increase the force ofthe emitter housing and detector housing on the concha site in the holdposition and in a direction toward the base so as to decrease the forceof the emitter housing and the detector housing on the concha site inthe hold position. The stabilizer may have an ear hanger that restsalong the back of the ear and couples to at least one of the legs andthe sensor cable.

Another aspect of an ear sensor comprises providing a sensor body havinga base, legs extending from the base and an optical housing disposed atends of the legs distal the base. An optical assembly is disposed in thehousing. The sensor body is flexed so as to position the housing over aconcha site. The sensor body is unflexed so as to attach the housing tothe concha site and position the optical assembly to illuminate theconcha site.

In various embodiments, an ear surface conforming member is molded to atleast a portion of the housing so as to physically couple the housing tothe concha site and block ambient light from the optical assemblyaccordingly. The force of the housing against the concha site isadjusted. The adjusting comprises positioning a force adjustment ring onthe sensor body so as to encircle the legs. The positioning comprisessqueezing a ring release so as to move ring grips away from the legs,moving the force adjustment ring along the legs and toward the housingso as to increase the force of the housing on the concha site, andmoving the force adjustment ring along the legs and away from thehousing so as to decrease the force of the housing on the concha site.

In other embodiments, an aspect of the ear sensor comprises supportingat least a portion of the weight of the sensor body and correspondingsensor cable so as to reduce the force needed to attach the housing tothe concha site. The supporting comprises attaching at least one of thesensor body and sensor cable to an ear hook placed over the ear.

A further aspect of an ear sensor comprising a clip means having aflexed position and an unflexed position. An optical means transmitsmultiple wavelength light into a tissue site when activated and receivesthe light after attenuation by pulsatile blood flow within the tissuesite. The optical means is disposed on the clip means so that theoptical means can be positioned on a concha site in the flexed positionand pinched against the concha site in the unflexed position. Aconnector means mechanically attaches to and electrically communicateswith a monitor. A cable means interconnects the connector means with theoptical means. In various embodiments, the clip means comprises aresilient frame means for securing the optical means in a fixed positionrelative to the tissue site. A housing means encloses the resilientframe means and the optical means. A cup means physically couples atleast a portion of the optical means to the concha site and blocksambient light from the optical means. An adjustable force means holdsthe clip means to the concha site. Alternatively, or in addition to, asupport means holds the clip means to the concha site.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of the pinna or external ear structure,including the concha;

FIGS. 2-3 illustrate various ear sensor embodiments;

FIGS. 2A-B are a side view and a perspective view of an ear budembodiment of an ear sensor;

FIGS. 3A-B are perspective views of a flexible ear pad embodiment of anear sensor;

FIGS. 4-7 illustrate various ear bud/pad attachment embodiments for aconcha site;

FIGS. 4A-D are side views of “C”-clip embodiments for attaching an earsensor to a concha site;

FIGS. 5A-B are perspective views of alligator clip embodiments forattaching an ear sensor to a concha site;

FIGS. 6A-B are perspective views of a clear adhesive disk embodiment forattaching an ear sensor to a concha site;

FIGS. 7A-C are perspective views of a flexible magnet disk embodimentfor attaching an ear sensor to a concha site;

FIGS. 8-10 illustrate various “hearing aid” style ear sensor embodimentsthat integrate the ear sensor with an attachment mechanism;

FIGS. 8A-B illustrate a concha-placed reflective sensor embodiment;

FIGS. 9A-B illustrate an “in-the-canal” reflective sensor embodiment;

FIGS. 10A-B illustrate “behind-the-ear” transmissive and/or reflectivesensor embodiments;

FIGS. 11-12 illustrate additional integrated ear sensor and attachmentembodiments;

FIGS. 11A-B illustrate an integrated ear lobe attachment andconcha-placed sensor embodiment;

FIGS. 12A-F illustrate a “Y”-clip sensor embodiment forconcha-placement;

FIGS. 13-16 illustrate various ear sensor attachment supportembodiments;

FIGS. 13A-F are side views of ear-hook support embodiments;

FIGS. 14A-B are perspective views of headband support embodiments;

FIGS. 15A-B are front and perspective views of a “stethoscope” supportembodiment;

FIG. 16 is a perspective view of a “headphone” support embodiment;

FIGS. 17-27 illustrate a concha-clip sensor embodiment having anorthogonally-routed sensor cable;

FIGS. 17A-B are perspective views of a concha-clip sensor;

FIGS. 18A-E are top, perspective, front, detector-side and emitter-sideviews, respectively, of a concha-clip sensor body;

FIG. 19 is an exploded view of an concha-clip sensor;

FIGS. 20A-B are assembly and detailed assembly views of a concha-clipsensor;

FIG. 21A-B are a mechanical representation and a correspondingelectrical (schematic) representation of a concha-clip sensor having aDB9 connector;

FIG. 22A-B are a mechanical representation and a correspondingelectrical (schematic) representation of a concha-clip sensor having aMC8 connector;

FIG. 23A-B are a mechanical representation and a correspondingelectrical (schematic) representation of a concha-clip sensor having aM15 connector;

FIGS. 24A-C are assembly step representations for installing an opticalassembly into a resilient frame and installing the resilient frame intoa sensor housing;

FIGS. 25A-E are top, perspective, front, side cross-section; and sideviews, respectively, of a force adjustment ring;

FIGS. 26A-F are top, disassembled perspective, assembled perspective,front, detector-side and emitter-side views of a concha-clip sensor bodyand corresponding force adjustment ring; and

FIGS. 27A-F are top, bottom, perspective, detector-side, front, emitterside and perspective views, respectively of an concha-clip sensor bodyhaving a parallel-routed sensor cable.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 2A-B illustrate an ear bud embodiment of an ear sensor 200 havingan emitter ear bud 210, a detector ear bud 220 and connecting cables230. The emitter ear bud 210 has a generally concave surface forattachment to the back of an ear. The detector ear bud 220 has agenerally convex surface 222 for attachment inside the ear at a conchasite opposite the emitter ear bud 210. Sensor cables 230 are attached atthe back of each ear bud having wires for electrical communications witha physiological monitor, such as a pulse oximeter. In particular, theemitter ear bud 210 includes wires for receiving emitter drive currentfrom a monitor and the detector ear bud 220 includes wires fortransmitting photodiode current to the monitor.

FIGS. 3A-B illustrate a flexible ear pad embodiment of an ear sensor 300having an emitter pad 310, a detector pad 320 and corresponding cables330. The sensor pads 310, 320 advantageously include a housing for eachof the emitter pad 310 and the detector pad 320, minimizing the numberof unique parts for the ear sensor. The detector pad 320 houses ashielded detector assembly (not shown). The emitter pad houses 310 anemitter (not shown). Both the detector pad 320 and the emitter pad 310are connected to a sensor cable 330. The pads 310, 320 have anintegrated bend relief 304 providing a finger grip. The pad face 306provides a generally planar, pliant contact surface that can adapt tothe curved front and back surfaces of a concha site. The pad face 306has a relatively large area to minimize contact force. The housing 302is injection molded of a pliant material. In one embodiment, thematerial is a medical grade thermoplastic elastomer.

FIGS. 2-3, above, illustrate various ear sensor embodiments. Althoughdescribed with respect to ear bud and flexible ear pad enclosures, thesensor emitter and detector may be enclosed in any number of housingshaving various sizes and shapes of ear tissue contact surfaces, may usevarious types of electrical interconnnect and use various materials soas to noninvasively measure blood parameters from the concha area of theear. As an example, the detector and emitter may both be mounted at oneend of a “Y”-shaped flex circuit that has a connector at the oppositeend. Although described above with respect to a detector placed insidethe ear and an emitter placed outside the ear, a suitable alternative isthe emitter inside and the detector outside the ear. Detector andemitter assemblies are described with respect to FIGS. 19-20, below.

FIGS. 4A-D illustrate “C”-clip embodiments 400 for attaching an earsensor 410 to a concha site. The clip 400 is adapted for use with eitherthe ear bud or the ear pad embodiments described above. The clip 400 hassensor mounts 420 fixedly attached to each end of a flexible “C”-shapedbody 422. The body 422 is made of a suitable material having anappropriate stiffness so as to provide a comfortable yet secureattachment to ear tissue. The sensor mounts 420 have mounting aperturessized for the ear buds or ear pads described above. The ear buds or padsare secured within the apertures with a friction fit or adhesive. In analternative embodiment, the sensor housings are molded or otherwiseintegrated with the sensor mounts.

As shown in FIGS. 4A-B, in one embodiment 401 the unflexed clip 400(FIG. 4A) is compressed between fingertips so that the clip ends 424 arecrossed (FIG. 4B) and the contact surfaces of the ear sensor 412 arefacing each other. The clip 400 is placed over the ear so that thedetector and emitter ear buds are on opposite sides of the ear. Fingerpressure on the clip 400 is then released so that the clip tension holdsthe sensor contact surfaces 412 against the concha tissue. As shown inFIGS. 4C-D, in another embodiment 403 the clip ends 424 are crossed inboth the flexed position (FIG. 4C) and the unflexed position (FIG. 4D).Otherwise, sensor attachment is as described above. Although describedabove as a “C”-shape, the clip body can be constructed of any of variousspringy, pre-formed materials having a variety of shapes and sizes so asto attach to ear tissue via compression and release between finger andthumb.

FIGS. 5A-B illustrate an alligator clip embodiment for attaching an earsensor to a concha site. The alligator clip 500 has opposing heads 510,each with a thru-hole 512 sized to accommodate either an ear pad sensor300 (FIG. 5A) or an ear bud sensor 200 (FIG. 5B). The alligator clip 500also has finger grips 520 each with a channel 530 for routing the sensorcabling 540. The alligator clip is compressed and released to positionand then attach the corresponding ear sensor to a concha site.

FIGS. 6A-B illustrate an adhesive disk embodiment for attaching an earsensor to a concha site. Clear disks 600 have an adhesive on bothsurfaces. The adhesive is bio-compatible on at least the tissue-facingsurface. The disks 600 are first attached to the sensor 200 or to aconcha site 10. Then the ear sensor 200 is attached on opposite sides ofthe concha tissue 10. The disks 600 are sized to accommodate either anear bud sensor 200, as shown, or an ear pad sensor 300 (FIGS. 3A-B).

FIGS. 7A-C illustrate a flexible magnet disk embodiment for attaching anear sensor to a concha site. Flexible magnetic disks 700, such as madefrom a mixture of a ferrite powder and a rubber polymer resin, arepermanently or temporarily attached to an ear sensor 200. The attachmentmay be by friction fit or a removable or permanent adhesive. The earsensor 200 is then placed on opposite sides of the concha site 10 andheld in place by the magnetic force of the disks. One or both disks maybe permanently magnetized during manufacture. The disks 700 are sized toaccommodate either the ear bud sensor 200, as shown, or the ear padsensor 300 (FIGS. 3A-B). In an alternative embodiment, each of the earsensor housings is at least partially composed of a high magneticpermeable material. One or both of the housings are magnetized. Inanother embodiment, one or more rare earth magnets are embedded in oneor both housings.

FIGS. 4-7, described above, illustrate various ear sensor attachmentembodiments. Although described with respect to clips and adhesive ormagnetic disks, the sensor emitter and detector may be attached to anear tissue site using various other materials and mechanisms. Forexample, ear buds or pads may attach via suction cups or disks. Also, anemitter and detector may be integrated with disposable adhesive padsconfigured with snaps or other mechanical connectors for attaching andremoving sensor leads from the disposable pads. In another embodiment, asensor may be mounted in the concha or the ear canal using an expandingfoam material that is first squeezed and then released after sensorplacement within the ear.

FIGS. 8A-B illustrate a concha-placed reflective sensor embodiment. Inone embodiment the sensor 800 has an ear canal extension 810 (FIG. 8B).In an embodiment, the ear canal extension has at least one emitter andat least one detector disposed proximate the extension surface so as totransmit light into ear canal tissue and to detect the transmitted lightafter attenuation by pulsatile blood flow within the ear canal tissue.In an embodiment, the emitter and detector are axially spaced on theextension. In an embodiment, the emitter and detector are radiallyspaced on the extension at a fixed angle, which may be, as examples, 30,45, 90, 120, 135, 160 or 180 degrees.

In an embodiment, the concha-placed sensor body 820 has at least oneemitter and at least one detector in lieu of an ear canal extensionemitter and detector. The sensor body emitter and detector are disposedproximate the concha surface so as to transmit light into concha tissueand to detect the transmitted light after attenuation by pulsatile bloodflow within the concha tissue. In an embodiment, the concha-placedsensor body 820 and the ear canal extension 810 both have at least oneemitter and at least one detector, creating a multi-site (concha and earcanal) reflective sensor. Connected with the sensor body 820 is a sensorcable 830 providing electrical communications between sensor body/earcanal emitter(s) and detector(s) and a monitor. Detector and emitterassemblies are described with respect to FIGS. 19-20, below.

FIGS. 9A-B illustrate an “in-the-canal” ear sensor embodiment. The earcanal sensor 900 has a base 910, an ear canal extension 920 and a sensorcable 930. Similar to the embodiment described above, the ear canalextension 920 has at least one emitter 922 and at least one detector 924disposed proximate the extension surface so as to transmit light intoear canal tissue and to detect the transmitted light after attenuationby pulsatile blood flow within the ear canal tissue. The emitter 922 anddetector 924 may be axially-spaced on the ear canal extension a fixeddistance. Alternatively, the emitter and detector may be radially-spacedon the ear canal extension at any of various angles, such as 30, 45, 90,120, 135, 160 or 180 degrees, to name a few. A sensor cable 930 isattached to the sensor so as to extend from the ear canal to acorresponding monitor.

FIGS. 10A-B illustrate “behind-the-ear” transmissive and/or reflectivesensor embodiments. The ear sensor 1000 has a concha-placed body 1010,an ear piece 1020, a connecting piece 1030 attaching the concha body1010 and the ear piece 1020 and a sensor cable 1040. In one embodiment,a concha-placed body 1010 houses a detector and the ear piece 1020houses an emitter opposite the detector so as to configure atransmissive concha sensor. In an embodiment, the concha-placed body1010 or the ear piece 1020 has both an emitter and a detector so as toconfigure a reflective concha sensor. In an embodiment, the concha body1010 and the ear piece 1020 are configured for multi-site transmissiveand/or reflective concha tissue measurements. In an embodiment, theconcha body 1010 also has an ear canal extension (see, e.g. 810 FIG.8B), which may also have an emitter and detector for multi-site conchaand ear canal measurements. A sensor cable 1040 extends from the earpiece 1020 as shown. Alternatively, a sensor cable extends from theconcha body, such as shown in FIG. 8B, above.

FIGS. 11A-B illustrate a concha sensor 1100 having an alligator clip1110, a concha piece 1120, a ear back piece 1130, a lobe attachment 1140and a sensor cable 1150. In an embodiment, the alligator clip 1110attaches to the ear lobe 20 so as to provide the physical support for aconcha sensor 1100. A convex body 1122 extends from the concha piece1120. A detector disposed at the convex body 1122 surface is disposedagainst the concha tissue 10. A concave surface 1132 is defined on theback piece 1130 and positioned behind the ear. An emitter disposed atthe concave surface 1132 is disposed against the ear wall opposite theconcha detector. The concha piece 1120 and ear back piece 1130 are“springy” so as to securely contact the concha tissue 10 under the forceof the alligator clip 1110, but without undue discomfort. In anembodiment, the lobe attachment 1140 also has an emitter and detector soas to provide multi-site ear tissue measurements at the ear lobe 20 andthe concha 10.

FIGS. 12A-F illustrate a “Y”-clip ear sensor 1200 having a base 1210, apair of curved clips 1220 extending from the base, an emitter assembly1230 extending from one clip end and a detector assembly 1240 extendingfrom another clip end. The clips 1220 are tubular so as to accommodatewires from the emitter/detector assemblies, which extend from apertures1212 in the base. Each assembly has a pad 1232, a molded lens 1234 and alid 1236, which accommodate either an emitter subassembly or a detectorsubassembly. The Y-“clips” flex so as to slide over the ear peripheryand onto either side of the concha. The integrated emitter and detector,so placed, can then transmit multiple wavelength light into the conchatissue and detect that light after attenuation by pulsatile blood flowwithin the concha tissue.

FIGS. 13A-F illustrate ear hook sensor support embodiments having an earhook 1300 with cable 1310, fixed 1320 or sliding 1330 support for eitheran alligator clip or a “Y”-clip sensor. These embodiments are alsoapplicable to “C”-clip sensors and alligator clip sensors, among others.

FIGS. 14A-B illustrate headband sensor support embodiments. In oneembodiment, the headband 1400 secures a concha body (FIGS. 8A-B) or anear canal sensor (FIGS. 9A-B) by placement over the ear. In anotherembodiment, the headband 1400 provides a cable support for an ear clipsensor.

FIGS. 15A-B illustrate a “stethoscope” 1500 sensor support embodiment.In this embodiment, one ear piece 1510 is integrated with an ear canalsensor 1520, such as described above with respect to FIGS. 9A-B. Inanother embodiment, both stethoscope ear pieces 1510 are integrated withear canal sensors for multi-site (both ears) blood parametermeasurements.

FIG. 16 illustrates a “headphone” 1600 support embodiment. In oneembodiment (not shown), a headphone ear piece secures a concha body(FIGS. 8A-B) or an ear canal sensor (FIGS. 9A-B) by placement over theear, in a similar manner as described with respect to FIGS. 14A-B. Inanother embodiment, the headphone 1600 provides a “ring-shaped” earpiece1610 that provides a cable support 1612 for an ear clip sensor 1200, asshown.

FIGS. 17A-B illustrate a concha-clip ear sensor 1700 embodiment having asensor body 1800, a connector 1710 and a sensor cable 1720 providingcommunications between the sensor body 1800 and the connector 1710. Asdescribed in further detail with respect to FIGS. 18A-E, the sensor body1800 has resilient legs that are manually flexed so as to slide over anear periphery and onto either side of a concha site. As described infurther detail with respect to FIG. 19, the sensor body 1800incorporates an optical assembly 1910 (FIG. 19) configured to transmitmultiple wavelength light into the concha tissue and detect that lightafter attenuation by pulsatile blood flow within the concha tissue. In aparticular embodiment, the sensor body 1800 has an emitter housing 1840(FIGS. 18A-E) configured to fit inside the ear and a detector housing1850 (FIGS. 18A-E) configured to fit outside the ear. In otherembodiments, the sensor body is configured so as to place an emitteroutside the ear and a detector inside the ear. In an embodiment, thesensor body 1800 is configured so that the sensor cable 1720 extendsgenerally perpendicular to the sensor body 1800, as shown and describedwith respect to FIGS. 17-26. In another sensor body embodiment 2700(FIGS. 27A-F) the sensor cable 1720 extends generally parallel to thesensor body, as described in further detail with respect to FIGS. 27A-E,below. Although the sensor body 1800, 2700 as described below has legs1830 extending from a base 1810 so as to generally form a “U”-shape, thesensor body 1800, 2700 can be constructed of any of various resilient,pre-formed materials having a variety of shapes and sizes so as toattach to ear tissue, such as a concha site or ear lobe site.

FIGS. 18A-E further illustrate a sensor body 1800 having a base 1810, astrain relief 1820 formed at a side of the base 1810 and a pair ofresilient legs 1830 extending from the base 1810. The strain relief 1820has a cable aperture 1822 that accommodates the sensor cable 1720 (FIGS.17A-B). An emitter housing 1840 extends from one leg 1830 and a detectorhousing 1850 extends from the other leg 1830. The legs 1830 accommodatecable conductors extending between the connector 1710 (FIGS. 17A-B) andan optical assembly 1910 (FIG. 19) located in the housings 1840, 1850.Each housing 1840, 1850 has an optical end 1842, 1852 (FIG. 20B) havingan aperture 1844, 1854 (FIG. 20B) that passes light from the emitterhousing 1840 to the detector housing 1850. In an embodiment, thehousings 1840, 1850 fit on either side of a concha tissue site so thatlight is transmitted from an emitter 1916 (FIG. 19), through the conchatissue and received by a detector 1912 (FIG. 19), as described in detailbelow. In an embodiment, the emitter housing 1840 fits within the earand the detector housing 1850 outside the ear. In an embodiment, a cup1860 extends from the detector housing 1850. The cup 1860 has agenerally circular edge and a curvature that accommodates the surfacebehind the ear. Accordingly, the cup 1860 advantageously provides a morecomfortable and secure fit of the detector housing 1850 to the ear andfurther functions as a light shield, blocking external light sourcesfrom the detector 1912. The resilent legs 1830 are manually flexed sothat the emitter housing 1840 is moved away from the detector housing1850 so as to position the detector housing 1850 and emitter housing1840 over opposite sides of a concha site. The legs are then released toan unflexed position so that the concha site is grasped between thedetector housing 1850 and emitter housing 1840.

FIGS. 19-20 further illustrates a concha-clip ear sensor 1700 having aconnector 1710 in communications with a sensor body 1800 via a sensorcable 1720. The sensor body 1800 has an optical assembly 1910, aresilient frame 1920, a sensor housing 1930 and lenses 1940. As shown inFIGS. 19-20, the optical assembly 1910 has a detector 1912, a detectorshield 1914, a light barrier 1915, an emitter 1916 and white electricaltape 1918. The cable 1720 has emitter wires 1722 and detector wires 1724that are soldered to the emitter 1916 and detector 1912, respectively,and communicate emitter drive signals and detector response signalsto/from the connector 1710.

Also shown in FIGS. 19-20, the resilient frame 1920 has an emitterchannel 1926 terminating at an emitter holder 1924, a detector channel1927 terminating at a detector holder 1925, a strain relief 1928 and aframe hole 1929. The optical assembly 1910 fits within the resilientframe 1920. In particular, the emitter wires 1722 are disposed withinthe emitter channel 1926, the detector wires 1724 are disposed in thedetector channel 1927, the emitter is disposed in the emitter holder1924 and the detector 1912 and corresponding shield 1914 and lightbarrier 1915 are disposed in the detector holder 1925. In an embodiment,the sensor housing 1930 is a one piece silicon skin disposed over theresilient frame 1920 and the optical assembly 1910, as described withrespect to FIGS. 24A-C, below. In an embodiment, the resilient frame1920 is a polypropylene/santoprene blend. The lenses 1940 are disposedwithin housing apertures 1844, 1854. In an embodiment, the lenses 1940are formed from a translucent silicone adhesive. In an alternativeembodiment, the lenses 1940 are separately formed from clear siliconeand glued into place with a translucent silicone adhesive.

FIGS. 21-23 further illustrate concha-clip sensor embodiments 2100,2200, 2300 having a DB9 connector 2130 (FIGS. 21A-B), a MC8 connector2230 (FIGS. 22A-B) or a M15 connector 2330 (FIGS. 23A-B). The sensorbodies 2110, 2220, 2330 have red and IR emitters 2112, 2212, 2312 anddetectors 2114, 2214; 2314 in communication with connectors 2130, 2230,2330 via emitter wires 2152, 2252, 2352 and detector wires 2154, 2254,2354. Sensor ID resistors 2132, 2232, 2332 are mounted in parallel withthe emitters, and can be read by a monitor generating currents below theemitter-on thresholds. Compatibility resistors 2134, 2334 can be read byother monitor types. EEPROMs 2136, 2236, 2336 programmed with varioussensor information can be read by more advanced monitors. Shield wires2156, 2256, 2356 provide conductive paths via the connectors to a commonshield ground. In an embodiment, ID resistors are 12.7 KΩ, compatibilityresistors are 6.81 KΩ, and EEPROMs are 1-wire, 20K bit memoriesavailable from Maxim Integrated Products, Inc., Sunnyvale, Calif.

FIGS. 24A-C illustrate integration of the optical assembly 1910 disposedat the end of a sensor cable 1720, the resilient frame 1920 and thesensor housing 1930. As shown in FIG. 24A, the optical assembly 1910 isthreaded into the sensor housing 1930. In particular, in a couple steps2401-2402, the optical assembly 1910 is inserted into the sensor housing1930 through the cable aperture 1822. In a further couple steps2403-2404, the optical assembly 1910 and portions of the attached sensorcable 1720 are pulled through the cable aperture 1822 and out of aU-slot 1932 of the sensor housing 1930.

As shown in FIG. 24B, in a step 2405, the optical assembly 1910 isintegrated with the resilient frame 1920 to form a frame assembly 2490.In particular, the detector assembly 1919 is inserted into a detectorholder 1925 to form a framed detector 2495. Also, the emitter 1916 isinserted into an emitter holder 1924 to form a framed emitter 2495.

As shown in FIG. 24C, the frame assembly 2490 is integrated with thesensor housing 1930 to form the sensor body 1800. In several steps2406-2408 the framed emitter 2494 is inserted into a pocket within theemitter housing 1840. In a couple additional steps 2409-2410, the frameddetector 2495 is inserted into a pocket within the detector housing1850. In a step 2411, a housing post 1934 is inserted into the framehole 1929. In several additional steps 2412-2414, excess cable 1720 isremoved from the sensor housing 1930 via the cable aperture 1822, andthe U-slot 1932 is closed and sealed with an adhesive. The resultingsensor body 1800 is described in detail with respect to FIGS. 18A-E,above.

FIGS. 25-26 illustrate a force adjustment ring 2500 that slidablyattaches to the sensor body 1800 so as to adjust the force of the sensorhousings 1840, 1850 against concha tissue. The ring 2500 forms agenerally oval opening 2526 having a pair of opposing sensor grips 2520generally centered along a long axis of the opening 2526 and a pair offinger releases 2510 generally centered along a short axis of theopening 2526. The sensor grips 2520 have toothed faces 2525 configuredto contact the sensor body legs 1830. The finger releases 2510 allow thering to be squeezed between a finger and thumb, say, so as to compressthe ring short axis, thereby lengthening the ring long axis andreleasing the toothed faces 2525 from the legs 1830. In this manner, thering 2500 can be positioned closer to or farther from the housings 1840,1850 so as to increase or decrease the force on a concha tissue site.

FIGS. 27A-F illustrate an sensor body 2700 configured for aparallel-routed sensor cable, as compared with the sensor body 1800(FIGS. 18A-E) configured for a perpendicular-routed sensor cable, asdescribed above. The sensor body 2700 has a base 2710, a strain relief2720 formed at a bottom end of the base 2710 and a pair of resilientlegs 2730 extending from an opposite end of the base 2710. The strainrelief 2720 has an aperture 2722 that accommodates the sensor cable 1720(FIGS. 17A-B). An emitter housing 2740 extends from one leg 2730 and adetector housing 2750 extends from the other leg 2530. The legs 2730accommodate cable conductors extending between a connector 1710 (FIGS.17A-B) and an optical assembly 1910 (FIG. 19) located in the housings2740, 2750.

Each housing 2740, 2750 has an optical end having an aperture thatpasses light from the emitter housing 2740 to the detector housing 2750.In an embodiment, the housings 2740, 2750 fit on either side of a conchatissue site so that light is transmitted from an emitter of the opticalassembly, through the concha tissue and received by a detector of theoptical assembly. In an embodiment, the emitter housing 2740 fits withinthe ear and the detector housing outside the ear. In an embodiment, acup 2760 extends from the optical end of the detector housing 2750. Thecup 2760 has a generally circular edge and a curvature that accommodatesthe outside curvature of the ear. Accordingly, the cup 2760advantageously provides a more comfortable and secure fit of thedetector housing 2750 to the ear and further functions as a lightshield, blocking external light sources from the detector assembly.

A sensor body 1800 (FIGS. 18A-E), 2700 (FIGS. 27A-F) is described abovewith respect to directly flexing resilient legs in order to space apartemitter and detector housings for placement on a concha site. In anotherembodiment, a pair of finger levers can extend from the legs to aposition below the sensor body base opposite the resilient legs. Thefinger levers can be squeezed between finger and thumb so as to flex theresilient legs for concha site placement.

In a particular advantageous embodiment, a single finger lever canextend from one leg to a position below the base. This single fingerlever can be squeezed using a sensor cable portion extending from thesensor body base for leverage. Such a single finger lever configurationeliminates potential discomfort from a second lever poking a patient'sneck area.

An ear sensor has been disclosed in detail in connection with variousembodiments. These embodiments are disclosed by way of examples only andare not to be construed as limiting the scope of the claims that follow.One of ordinary skill in art will appreciate many variations andmodifications.

1. An ear sensor for optically measuring physiological parametersrelated to blood constituents by transmitting multiple wavelengths oflight into a concha site and receiving the light after attenuation bypulsatile blood flow within the concha site, the ear sensor comprising asensor body, a sensor connector and a sensor cable interconnecting thesensor body and the sensor connector, the sensor body comprising: abase; a first leg extending from the base to a detector housing; asecond leg extending from the base to an emitter housing; an opticalassembly having an emitter and a detector; the emitter disposed in theemitter housing; the detector disposed in the detector housing; the legshaving an unflexed position with the emitter housing proximate thedetector housing and a flexed position with the emitter housing distalthe detector housing; the legs moved to the flexed position so as toposition the detector housing and emitter housing over opposite sides ofa concha site; and the legs released to the unflexed position so thatthe concha site is grasped between the detector housing and emitterhousing.
 2. The ear sensor according to claim 1 further comprising: aresilient frame; and a one piece molded skin disposed over the resilientframe.
 3. The ear sensor according to claim 2 further comprising: a cupdisposed proximate the detector housing; and the cup having a surfacethat generally conforms to the curvature of the concha site so as tocouple the detector to the concha site and so as to block ambient light.4. The ear sensor according to claim 3 further comprising: a sensorcable having a first end and a second end; a plurality of wires disposedwithin the sensor cable; the wires extending from the first end of thesensor cable and disposed within a plurality of channels defined by theresilient frame; the wires electrically and mechanically attached to theoptical assembly; a connector attached to a second end of the sensorcable; and the wires electrically and mechanically attached to theconnector so as to provide communications between the connector and theoptical assembly.
 5. The ear sensor according to claim 4 furthercomprising a stabilizer that maintains the position of the detectorhousing and the emitter housing on the concha site.
 6. The ear sensoraccording to claim 5 wherein the stabilizer comprises a a ring thatencircles the legs; the ring having a hold position disposed against thelegs and a release position spaced from the legs; a release that, whenpressed, moves the ring from the hold position to the release position,allowing the ring to slidably move along the legs in a direction awayfrom the base so as to increase the force of the emitter housing anddetector housing on the concha site in the hold position and in adirection toward the base so as to decrease the force of the emitterhousing and the detector housing on the concha site in the holdposition.
 7. The ear sensor according to claim 5 wherein the stabilizercomprises an ear hanger that rests along the back of the ear and couplesto at least one of the legs and the sensor cable.
 8. The ear sensormethod comprising: providing a sensor body having a base, legs extendingfrom the base and an optical housing disposed at ends of the legs distalthe base; disposing an optical assembly in the housing; flexing thesensor body so as to position the housing over a concha site; andunflexing the sensor body so as to attach the housing to the concha siteand position the optical assembly to illuminate the concha site.
 9. Theear sensor method according to claim 8 further comprising molding an earsurface conforming member to at least a portion of the housing so as tophysically couple the housing to the concha site and block ambient lightfrom the optical assembly accordingly.
 10. The ear sensor methodaccording to claim 9 further comprising adjusting the force of thehousing against the concha site.
 11. The ear sensor method according toclaim 10 wherein the adjusting step comprises positioning a forceadjustment ring on the sensor body so as to encircle the legs.
 12. Theear sensor method according to claim 11 wherein the positioning stepcomprises: squeezing a ring release so as to move ring grips away fromthe legs; moving the force adjustment ring along the legs and toward thehousing so as to increase the force of the housing on the concha site;and moving the force adjustment ring along the legs and away from thehousing so as to decrease the force of the housing on the concha site.13. The ear sensor method according to claim 9 further comprisingsupporting at least a portion of the weight of the sensor body andcorresponding sensor cable so as to reduce the force needed to attachthe housing to the concha site.
 14. The ear sensor method according toclaim 13 wherein the supporting comprises attaching at least one of thesensor body and sensor cable to an ear hook placed over the ear.
 15. Anear sensor comprising: a clip means having a flexed position and anunflexed position; an optical means for transmitting multiple wavelengthlight into a tissue site when activated and for receiving the lightafter attenuation by pulsatile blood flow within the tissue site; theoptical means disposed on the clip means so that the optical means canbe positioned on a concha site in the flexed position and pinchedagainst the concha site in the unflexed position; a connector means formechanically attaching to and electrically communicating with a monitor;and a cable means for interconnecting the connector means with theoptical means.
 16. The ear sensor according to claim 15 wherein the clipmeans comprises a resilient frame means for securing the optical meansin a fixed position relative to the tissue site.
 17. The ear sensoraccording to claim 16 further comprising a skin means for enclosing theresilient frame means and the optical means.
 18. The ear sensoraccording to claim 17 further comprising a cup means for physicallycoupling at least a portion of the optical means to the concha site andfor blocking ambient light from the optical means.
 19. The ear sensoraccording to claim 18 further comprising an adjustable force meansholding the clip means to the concha site.
 20. The ear sensor accordingto claim 18 further comprising a support means for holding the clipmeans to the concha site.